Process of making cuprammonium solution.



fum'rnn STATES raa nn'r OFFICE.

HENRY BERNSTEIN, OF PHILADELPHIA, PENNSYLVANIA.

PROCESS OF-MAKING CUPRAMMONIUM SOLUTION.

Specification of Letters Patent. Patented July 26, 1910.

No Drawing. Original application filed April 12, 1910, Serial No. 555,075. Divided and this application filed June 24, 1510.

To all whom it may concern:

.ployed in the manuiacture of artificial silll;

, and-it consists in adding viscous saccharine solution' such as molasses, to aqua ammonia solution and bringing the same into contact with metallic -,co.pper.

This application is filed as a division of -my application Serial No. 555,075, filed April 12, 1910.

It ,further consists in subjecting molasses -toaqua ammonia or ammonia gas, adding this to another solution aqua ammonia. and bringing the same into contact with metallic copper.

about two and one-half 24-) expense and in addition it is unhealthy" and disagree- It is known that cuprammoniuin solution can bemanufactured or made, by sub ecting metallic copper to an ammonia solution and forcing air through this liquid, butby this o'ssible to obtain or cent. of copper in solution and to retain it in the liquid. Im rovemcnts in the results obtamed bytiis process have'bcen made, by keeping the temperature down to a low degree, say below 5 C. \Vhen the temperature goes above the 5 C. copper hydroxid is precipitated, which reduces the copper strength and weakens the dissolving power of the solution for cellulose and in. some cases destroys the dissolving power. In ad dition, the solution is not stable and it must be'kept in a cool temperature. One of the principal objections to". this is the large n maintainingthe low temperature,

method it has only been able-for the workmen.

By my process Iain enabled to"prepare cu rammonium solution stronger thanhereto ore, sinceit is well known that, under ordinary temperatures, ll- 2% solution only .can be obtained, but by my" r'ocess I obtain a solution of five per cent.

5%), or above, of copper, also stable at the ordinary tem perature and having a strong dis olving power.

Serial No. 568,641.

In carrying out my invention I prefer to take a solution of aqua ammonia and add about two per cent. (2%) of molasses thereto. This molasses solution is then added to aqua ammonia, of suitable strength, and this last solution is brought into contact witlrtho metallic copper in any form, such as strips or shavings in a suitable vessel and air is then forced through the liquid. (bile any suitable solution may be employed, I prgfcrably take a strong aqua ammonia solution of about twenty per cent. (20/21) strength and dissolve the molasses substance therein to form a molasses solution. This molasses solution is added to an aqua ammonia solutioii, of fourteen to twenty per cent. of ammonia gas, and this solution is then placed or broughtinto contact with co per strips or shavings in a suitable receptac e and I then force airv or any suitable gas containing free oxygen through the liquid. By this, in

'troin six to eight hours, I obtain a solution of five per cent. (5%) or .over and I am en abled to dissolve at ordinary temperatures about eight per cent. (8%) of cellulose 50-- lution of great viscosity. I employ molosses by reason of its three component elements: first, sucrose, kept from crystallizing 5 be dissolved and kept stable at ordinary temperature.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1. The process of making cuprammoniuin solution, which consists in subjecting mctal-.

lution, adding the molasses solution to aqua ammonia of suitable strength, placing this solution into contact with copper in any form Such as strips or scraps, and then'forcmg air through the liquid.

I'IENRY BERNSTEIN. W'itnesses \VM. Carina lViEonnsi-niir, O. D; MCVAY. 

